Grinding and polishing machine



March 9 1926.

F. KUHN ET AL GRINDING AND POLISHING MACHINE Filed July 1922 4 Sheets-Sheet 1 I a I w 8 u m m I F 1 r wowwbozs FRANK. (4mm Lmmuca. Tamas March 9 1926.

F. KUHN ET AL GRINDING AND POLISHING MACHINE 4 She ets-Sheet 2 March 9 1926.

F. KUHN ET AL GRINDING AND POLISHING MACHINE Fiied July 24; 1922 4 Sheets-Sheet 5 5. M m Wm {WM g a M k W w w W 4 \s T m Q G Remap March 9 1926.

F. KUHN ET AL GRINDING AND POLISHING MACHINE 4 Sheets-Sheet 4 Filed July 24, 1922 FRANK. Rum.

Lamina. Tamas Patented Mar. 9, 1926.

FRANK KUH N AND LAURENCE' I-I-..THOMIAS, OF DETROIT, MICHIGAN; ASSIGNORS '10 AMERICAN- ELECTRICAL COMPANY, OF- DET ROIT; MICHIGAZBL A COR- PORATIONIIOF MICHIGAN.

GRINDING A'NIDu BOLISHING MACHINE.

A plication-Italian .24,1922. Serial No. 577,187.

To all whom 7'26 may] cmiccm:

Be it known that we, FRANK Kin-1N, and LAURnNcnI-I. THOMAS, both citizens of the United States of America, residing at Detroit, in the county of lVayne and State of Michigan, have invented certain new and useful Improvements in Grinding and Polishing Machines, of whichthe following is a specification, reference being bad therein inorematerial at these points thereby causing a rounding over of the corners which 7 is undesirable. Our. machine overcomes this trouble byproviding a means for relieving the pressure of the work against the grinding wheel-at the points in the cycle where the corners of thearticle are beingground.

Another-object of the invention isv to provide a work holder upon. which the article can be quickly clamped and which is adaoted for rotating the work in operative relation to a. grinding wheel.

A further objectv is to obtain ;a uniform relative inoveinentof the work acrossthe.

face of the grinding wheel whereby the grinding wheel will be worn down unrl ord ly over its entire Wonk-mg surface.

A still further object. is to provide ameans for stopping the rotation of the work. at

a predetermined point in its cycle of operation. i

Still other objects reside in the novel. teaparts which are hereinafter fully set forth.

In the drawings 1 Figure :1 is a plan view ofthe complete machine;

Figure ,2 is a sectional end elewation.

Figure 4 is a transverse section onthe line 4-4: of Figure 2;

Figure, 5 is a sectional plan view on the line 5 5 of Figure 2;

anpenlarged end view of {the Figure 6 is work holder Figure "4 is a section online 77 of In general construction-the machine consists of a horizontal base 1 provided with thelongitudinal guideways 2 on which is mounted the sliding platform extending brackets 4 are secured to the plat- .form 3 and are provided with hearings to receive the horizontalshaft 5, the axis of which preterablyforms an angle with the guideways 2 corresponding to the bevel of.

the work to be ground. A rockable frame (5 is supported on the shaft 5 by bearings? and at itsupper end providedwith the bearings 8 in which is journaled the rotatable hollow arbor .9. I

A work holder 10 is secured to one end of the arbor 9 and may be ofany suitable con- .struction to clamp a work piece thereto. As shown in the draw ngs, the work holder Upwardly .-1

is designed to receive an electric flat iron base 17 which has a. threaded aperture 17 which, is used in assembling the base to the iron. ,The work holder, therefore reierably consistsof a frame 11 having the bearing. surface 115 against which. the workpiece 17 may. be seated. The frame. 11 is ecured to the =arbor 9 by suitable .incans such as screwslQ which threadedlyv engage a collar keyed to the arbor 9. ,A shaft 14: is row is provided with a. threaded; portion 1% whi-chis adapted to enter thethreaded aperture 17 of firework-piece, Inorder to rotate the shaft l i, the hollow arbor 9 contains an-inner shaft 15 which is rotatably connected to the shaftl4t by means of the tures of constructionand, comb nation of gears 16 and 16. theoppositeend of the shaft is secured a hand wheel 17 so that by rotatingthe hand wheel the work piece 1nay be quickly clamped. to the work holder.

ML grinding wheellS is locatedin operat-ive relation to the work piece 17 and is rotablyniounted in the collar 13 and wheel 18 by suitable means such as the weight 19 which is attached to a cord 19 secured to the frame and operating over a pulley 20 in the upwardly extending portion 21 of the main frame 1.

For rotating the work piece 17 a motor 22 is provided which is mounted upon the platform 3 and drives the arbor 9 through suitable gearing. As shown, the power is trans mitted to a cross shaft 24 by means of the worm 25 and worm wheel 25 and from the cross shaft to the shaft 5 by means of a worm 26 and worm wheel 26 A sprocket wheel 27 is rotatably mounted upon the shaft 5 between suitable collars 28 and a clutch 29 is mounted upon the shaft 5 to transmit rotation thereof to the sprocket 27. The clutch is normally held in engagement with the sprocket by means of a spring 30 which is sleeved upon the shaft 5 between the end of the clutch 29 and the collar 31. For dis-- engaging the clutch a bell crank lever 32 is provided which is pivoted to a bracket 33 on the platform 3. The arm 32 of the bell crank lever is connected to the clutch 29 and is adapted to move the same longitudinally on the shaft 5. The other arm 32" of the bell crank lever extends at right angles to the first arm and engages with an arm 32-5 secured to the rockable frame 6. Upon a predetermined movement of the frame 6 away from the grinding wheel 18 the arm contacts with the bell crank lever 32 and disengages the clutch 29 from the sprocket 27. A second sprocket wheel 34 is secured to the arbor 9 and a chain 35 connects the sprockets 27 and 34.

In order that the grinding wheel will be worn down uniformly over its entire working surface the platform 3 is uniformly reciprocated relative to the frame 1. For accomplishing this purpose a vertical shaft 36 is rotatably mounted ina bushing 37 secured to the platform and is provided at its lower end with a heart shaped cam 38. The cam is rotated from the shaft 5 by means of the bevelled gears 39 and 39. Cooperating with the cam 38 are the rollers 40 and 40 which are respectively mounted upon the pins 41 and 41 secured to the horizontal base of the machine. The rotation of the shaft 5 causes a corresponding rotation of the cam which reciproca-tes the platform 3 on its guideways 2.

In order to relieve the pressure of the work upon the grinding wheel during the grinding of the corners of the work piece a cam or pattern 42 is secured to the arbor 9. The pattern is of the same general configuration as the work piece but has rounded corners 42 corresponding to the sharp corners 17* of the work piece. Cooperating with the pattern. is a roller bearing 43 which is rotatably mounted upon a pin 44 secured to an upwardly extending portion of the frame 45. The axis of the roller bearing is parallel to the axis of the rotating grinding wheel so that during the reciprocation of the carriage 3 the work piece is maintained the same distance from the grinding wheel throughout the reciprocation. In order to compensate for wearing down of the grinding wheel the roller 43 is adjustable transversely to its axis by any suitable means and as shown this consists of a member 46 secured to the pin 44 and movable relative to the frame 45. A rod 47 extending through the frame 45 is in threaded engagement with the member 46 and the various posi- -tions of adjustment may be obtained by turning the knob 4-8.

F or stopping rotation of the work piece it is only necessary to move the frame 6 away from the grinding wheel 18 thereby operat ing the clutch 29 but in order to stop the rotation at a predetermined point in the cycle of rotation a cam 49 is rotatably secured to the arbor 9. The cam is provided with an operating handle 50 for rotating the same about its axis. The lower part of the cam has a contour such that upon rotating the cam by means of the handle 50 the rockable frame 6 will be forced away from the grinding wheel and will operate the clutch 25) to stop the rotation of the work piece. However, when the rounded portion of the work piece is in contact with the rotating grind-- ing wheel the pressure angle of the cam surface is such that movement of the handle will not cause the frame to be rocked away from the grinding wheel.

In the operation of the machine the work piece 17 is first clamped upon the work holder 10, the cam 49 is then placed in its downward position which allows the frame to move toward the grinding wheel and brings the work in operative relation thereto. This movement of the frame toward the grinding wheel also engages the clutch 28) to the sprocket 2! which starts the work piece rotating. The work will then slowly revolve in contact with the grinding wheel but when the corners come into operative position the corresponding rounded portions of the cam 42 will force the frame away from the grimling wheel and thereby relieve the pressure. By properly proportioning the cam 42 the work will be uniformly ground over its entire contour. After the work has been sufficiently ground the operator may withdrai the frame by means of the handle 50 on the cam 49 but pressure upon this handle will not move the frame until the work piece is in a predetern'iined position. \Vhen the nose of the base is in operative position, however, the handle 50 may be operated which rocks the frame out of position and stops the rotation of the work.

and aswinging frame, of a rotatable patern mounted on one of said frames, a cooperating abutment on the other of said frames, means for yieldingly urging said swinging frame in one direction, means for rotating said pattern whereby said swinging frame is oscillated in the opposite direction through a limited distance, means for stopping rotation of said pattern operable by the swinging of said frame in said opposite direction through a distance greater than said limited distance, and manually operable means for swinging said frame through said greater distance, said manually operable means being inoperative to move said frame until the later is moved a predetermined distance in said opposite direction.

2. The combination with a fixed frame and a swinging frame, of a rotatable work holder mounted on said swinging frame, a grinder wheel mounted on said fixed frame, a pattern rotatable with said work holder, a cooperating abutment engageable with said pattern, means for yieldingly urging said swinging frame toward said grinder wheel, said swinging frame being swung away from said grinder wheel by the engagement of said pattern and said abutment, driving means for rotating said worklholder, means for stopping rotation of said work holder operable only upon the swinging of said frame through a distance greater than the normal swinging caused by saidpattern. and manually operable means adapted to swing said frame beyond its normal movement, said means being inoperative except when said frame is a predetermined distance away from said grinder wheel.

3. In a machine for grinding articles of irregular contour, the combination with a rotating grinder wheel, of a swinging frame movable relative thereto, a rotatable work holder on said frame, a clutch mounted coaxially of said swinging frame, driving means between said clutch and said work holder, a pattern rotatable with said work holder, a cooperating abutment engageable with said pattern, means for yieldingly urging said fran'ie toward said grinder wheel, said frame being swung away from said grinder wheel by the engagement of said pattern and said abutment, a lever adapted to disconnect said clutch from said work holder, an arm on said swinging frame adapted to actuate said lever only upon the swinging of said frame through a distance greater than the normal swinging caused by said pattern and manually operable means adapted to swing said frame beyond its normal movement, said means being inoperative except when said frame is a predetermined distance away from said grinder wheel.

l. In a machine for grinding articles, the combination with a fixed frame and a swinging frame, of a work holder on one of said frames, means for rotatin said workholder, means operated by the rotation of said work holder for swinging said frame, a cam pivotally mounted upon one of said frames and a cooperating abutment on the other fran'ie, said cam being provided with a non-lifting portion normally engageable with said abutment, and also being provided with a lifting portion engageable with said abutment when said swinging frame is rocked 'a predetermined distance relative to said fixed frame, said non-lifting portion preventing engagement of said lifting portion until the aforesaid predetermined rocking movement is effected.

5. In a machine for grinding articles, the combination with a fixed frame and aswinging frame, of a work holder on one of said frames, means for rotating said work holder, means operated by the rotation of said work holder'for swinging said frame, a lever pivotally mounted on said swinging frame, a handle at one end of said lever, a cam at the opposite end of said lever, and a cooperating abutment on said fixed frame, said cam being provided with a non-lifting portion engageable with said abutment and also being provided with a liftingportion engageable with said abutment when said swinging frame is rocked a. predetermined distance relative to said fixed frame, said non-lifting portion preventing engagement of said lifting portion until the aforesaid predetermined rocking movement is effected.

6. In a machine for grinding articles of irregular contour, the combination with a rotating grinder wheel, of a swinging frame movable relative thereto, a rotatable work holder on said frame, a pattern rotatable with said work holder, a cooperating abutment engageable with said pattern, and manually operable means for stopping the rotation of the work and withdrawing the same from said grinding wheel comprising a lever having its fulcrum axially aligned with said work holder, a cam upon said lever, a cooperating abutment engageable with said cam, said cam being provided with a lifting portion engageable with saidabutment when said pattern is in a predetermined point in its cycle of rotation and being provided also with a portion engageable with said abutment to prevent said lifting port-ion from engagement therewith.

In testimony whereof we aflix our signa-,

tures.

FRANK KUHN. LAURENCE H. THOMAS. 

